The present invention relates to medical device packages. More particularly, the present invention relates to medical device packages having a gas permeable lid and a clear plastic tub.
Medical devices, such as prefillable syringes and the like are frequently packaged in multi-unit packages that must be surface decontaminated prior to introduction into a controlled sterile environment where the devices are filled with medication or otherwise further manipulated prior to use, or used in a surgical procedure.
There are numerous methods used to sterilize the devices within the packages, such as gas sterilization utilizing ethylene oxide or steam sterilization. However, different methods, such as ultraviolet light sterilization, are often used for decontamination of the surfaces of the packages prior to subsequent use. It would be desirable to have a medical device package capable of use in a multitude of sterilization and decontamination techniques and yield a high level of kill of microorganisms.
A common type of package utilized in the field of medical packaging is the peel-open package. Such a package commonly comprises a thermoplastic film that is formed to a desired package shape and a lid material is then sealed to the plastic film to contain he packaged product.
The common thermoplastic film packages described above are often utilized to package individual medical devices, as the film does not provide sufficient protective characteristics for use in a multiunit package which may house delicate items. Therefore, there is a need for a multiunit package, such as a tub, that can withstand the sterilization and decontamination processes and provide a sufficient mechanical barrier to prevent damage to the items held within the package.
The lid material used is commonly a non-woven fiber arranged such that it has a microporous structure, such as Tyvek(copyright). The microporous fiber arrangement allows gas to penetrate but has a sufficiently small pore size to block the transfer of microorganisms.
The microporous fiber arranged lid is, therefore, useful in sterilization techniques utilizing a gas, such as the aforementioned ethylene oxide and steam sterilization techniques.
The Tyvek(copyright) lid, however, does not allow the transmission of ultraviolet light that may be used as a package surface decontamination technique. Specifically, the heat seal between the lid and tub cannot be made flush with the edge of the tub flange due to processing limitations and the potential for Tyvek(copyright) tearing during peel open if an unsealed lip of Tyvek(copyright) is not available for initiation of the peeling process. Therefore, there is a region outside of the heat seal, covered by Tyvek(copyright), which is not maintained sterile with the contents of the package. This area can be inadvertently contaminated during, manipulation of the package, as can the entire external surface of the package. However, unlike the remainder of the external surface, which can be directly exposed to ultraviolet light for decontamination, the area outside of the heat seal is blocked to the ultraviolet light by the opaque Tyvek(copyright) material on top and opaque tub material below.
Therefore, it would be desirable to utilize an ultraviolet-light transmissive plastic tub that can allow transmission of light to the underside of the heat seal area between the lid and tub to kill all microorganisms residing therein. Plastics which transmit light in the ultraviolet range typically transmit an even greater percentage of incident light in the visible (400-700 nanometer) range, resulting in a clear appearance.
An advantage of utilizing a clear plastic tub, as opposed to an opaque one is that it would allow for visual inspection of the contents of the package to determine if any of the items are damaged. This aspect offers quality control advantages to a manufacturer, as well as allow end users to ensure they are not receiving or using damaged items. Another advantage of utilizing a clear plastic tub would be the possible use of an automated visual quality system. For example, a package and its contents may be imaged and compared to a stored visual image to determine if the contents of the package are damaged. Such an automated system could provide a cost savings, as well as an increased quality control efficiency.
Alternatively, a Tyvek(copyright) lid having an ultraviolet-light transmitting plastic border that is heat sealed to a plastic tub would allow for light sterilization of the area between the lid and tub. Such a lid may be utilized with either a clear plastic tub, or with an opaque tub and allow for light to penetrate the area around the heat seal.
Another problem associated with Tyvek(copyright) lids that are known in the art, is the possibility of the Tyvek(copyright) lid shearing or tearing when peeled to open the package and thereby generating unacceptable particulate matter that may contaminate the contents of the package.
It is known in the art to coat a Tyvek(copyright) lid in an effort to reduce particulate generation, as well as prevent the lid from separating or delaminating when the heat seal strength between the lid and tub is too great. A disadvantage to this coating technique is that it has the tendency to reduce the pore size of the Tyvek(copyright) material; thereby preventing the necessary transmission of gas across the lid material or increasing the cycle time of a sterilization procedure.
It would be desirable to have a gas permeable uncoated Tyvek(copyright) lid that has a smooth continuous plastic border that is resistant to shearing and does not generate particulate matter when peeled away to access the contents.
A lid with a smooth continuous plastic border would also be desirable for use with an automated lid removal system, such as a hot knife or laser cutter that would cut the plastic border inside of the heat seal region, as an alternative to a peel-open technique.
Therefore, it is an object of the present invention to provide a medical device package which has an ultraviolet-transmissive and clear plastic tub to allow for visual inspection of the contents, as well as to allow for the transmission of microorganism killing light.
It is a further object of the present invention to provide a medical device package having a clear plastic tub that has sufficient strength characteristics to hold and protect from damage the contents of the package.
It is a further object of the present invention to provide a medical device package having a microporous, gas permeable lid that has a plastic border to minimize the creation of particulate matter when opening the package.
It is a further object of the present invention to provide a medical device package having a microporous, gas permeable lid with an ultraviolet-transmissive plastic border to facilitate the transmission of light during a decontamination process.
The present invention meets these objects by providing a medical device package having a tub having a four sided base from which four walls extend upwardly at approximately ninety degrees. The walls terminate at a first flange which extends outwardly at an angle of approximately ninety degrees from the four walls. The first flange terminates at four top walls that extend upwardly at approximately ninety degrees from the flange. The four top walls terminate at a second outwardly extending flange, which extends at an angle of approximately ninety degrees from the four top walls. The tub is formed of an ultraviolet-light transmitting plastic that is capable of withstanding exposure to gas sterilization and surface decontamination processes without degradation of the tub.
The present invention also includes a lid having a gas permeable central portion and a transparent plastic film attached to the central portion along its periphery. The plastic film overlaps the central portion when attached to assure a reliable bond of the two items. The transparent plastic film has a high shear resistance to avoid producing particulate matter when an opening force is applied. The transparent plastic film also allows transmission of ultraviolet light. These and other features of the present invention can be best understood from the following specification and drawings.